Pneumatic flip-flop relay

ABSTRACT

A pneumatic snap-action toggle relay comprising a sealed housing separated by a diaphragm and switch means coupled to the diaphragm and actuated by buckling of the diaphragm. The diaphragm is made from a relatively thin, stiff toggle member, normally of flat planar configuration but resiliently buckleable laterally of the plane when a force parallel to the plane of the toggle member is applied to an edge of the toggle member. The housing in which the diaphragm is positioned contains a flexible wall and a resilient force, such as air pressure or a mechanical spring applied to the outside of the wall causes the diaphragm to buckle. A control member is mounted on a rotatable edge of the toggle member and is journaled in a wall of the housing. The control member can contain arms which actuate electrical switches and/or can contain grooves which are aligned with ports passing through the journal housing wall as the control member rotates. Other grooves are provided in the control member to direct the flow of fluid pressure through the side of the housing into which the toggle member is buckled so as to switch or buckle the toggle member to the other side of the housing. A mechanical actuator can be attached to the diaphragm or to the control member for a mechanical output.

United States Patent Bond- 1 PNEUMATIC FLIP-FLOP RELAY [76] Inventor: Charles R. Bond, 2241 Boston, SE,

Grand Rapids, Mich. 49506 [22] Filed: Oct. 3, 1973 [21] Appl. No.: 403,208

[52] US. Cl. 200/83 P, 200/67 DB, 200/83 B, 200/333 [51] Int. Cl. H0lh 35/34 [58] Field of Search 200/83 A, 83 B, 83 N, 83 P, 200/83 Y, 83 Z, 67 R, 153 G, 159 B, 293,

Primary E.\'aminer-Robert K. Schaffer Assistant E.\"aminer-Gerald P. Tolin Attorney, Agent, or FirmMcGarry & Waters Mar. 18, 1975 [57] ABSTRACT A pneumatic snap-action toggle relay comprising a sealed housing separated by a diaphragm and switch means coupled to the diaphragm and actuated by buckling of the diaphragm. The diaphragm is made from a relatively thin, stiff toggle member, normally ot' flat planar configuration but resiliently bucklcablc laterally of the plane when a force parallel to the plane of the toggle member is applied to an edge of the toggle member. The housing in which the diaphragm is positioned contains a flexible wall and a resilient force, such as air pressure or a mechanical spring applied to the outside of the wall causes the diaphragm to buckle. A control member is mounted on a rotatable edge of the toggle member and is journaled in a wall of the housing. The control member can contain arms which actuate electrical switches and/or can contain grooves which are aligned with ports passing 25 Claims, 13 Drawing Figures 42 PATENTEU I 19 5 HEET 1 [IF 3 FIG. I

PATEHTED 81975 SHEU 2 BF 3 FIG. 5

PNEUMATIC FLIP-F LOP RELAY BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to pneumatic flip-flop relays. In one of its aspects, the invention relates to a pneumatic flip-flop relay of the latching type used to control electrical, mechanical or pneumatic switches.

2. State of the Prior Art Pressure operated switches are generally used to control electrical components. One type of electrical switch is illustrated in the U.S. Pat. No. 3,268,683 to Palmer. In this type of switch, a flexible diaphragm in a valve housing has an electrical contact mounted thereon and is movable between oneor two electrical contacts by differential pressure on a diaphragm. Snap springs, as disclosed in the U.S. Pat. No. 3,689,719 to Phillips et al., can be used in conjunction with flexible diaphragms to cause the diaphragm to snap between various positions.

Another type of flexible diaphragm type of snap action switch is disclosed in U.S. Pat. No. 3,513,410 to Budzick et al. Still another type of snap action switch is disclosed in the U.S. Pat. No. 1,684,530 to Bast. In the Bast mechanism, a metal diaphragm formed with a cavity is used to operate a monostable switch.

A bistable differential pressure operated switch is disclosed in the U.S. Pat. No. 3,363,072 to Moody. In the Moody device, a pair of flexible diaphragms are used to control the position of a switch element. A leaf spring, mounted between the flexible diaphragm and secured to the movable switch element, provides the latching and snap action of the switch element.

SUMMARY OF THE INVENTION According to the invention there is provided a pneumatic flip-flop relay for electrical, mechanical or fluid pressure controls wherein the diaphragm or portions thereof form a bistable element. The pneumatic relay comprises a sealed housing, separated by a diaphragm, and switch means coupled to the diaphragm and actuated by buckling of the diaphragm. A relatively thin, stiff toggle member forms a part of the diaphragm and normally has a flat planar configuration but is resiliently buckleable laterally of the plane by the application of a force to the edge of the toggle member. Means are provided for applying the force to the edge of the toggle member to deform or buckle the toggle member to one side of the housing. The force is desirably applied resiliently by means of differential air pressure to a flexible wall of the housing adjacent the edge of the flexible member, or by spring pressure.

The toggle member desirably is formed from two portions of a sheet of stiff material, such as high density polyethylene, polyvinylchloride, etc., which planar portions are hinged together along a common edge.

The switch means includes a control member mounted on a rotatable edge of the toggle member and journaled in a portion of the housing for rotational movement between a first position wherein the toggle member is buckled to one side of the housing and a second position wherein the toggle member is buckled to the other side of the housing. In one embodiment, control arms extend from the control member and are positioned to operate electrical switch contacts as the control member moves from the first to the second position. In another embodiment, the control member in- 2 cludes a groove in facial contact with the journal, which groove is adapted to be in registry with a pair of ports in the journal when the control element is in the first rotational position but out of registry with the ports when the control member is in the second rotational position. In still another embodiment, a mechanical output arm is secured to the control element or the diaphragm to provide a mechanical output for the relay.

The control member also includes means for applying differential pressure to either side of said diaphragm. The differential pressure applying means includes grooves in the control housing communicating with one side of the housing when the control member is in the first position and communicating with the other side of the housing when the control memeber is in the second poisition. Ports extend through the journal and communicate with the grooves for selectively switching the toggle member from one side of the housing to the other and vice versa. One or both of the ports can be connected with a means for supplying pressurized air flow at a controlled rate so that the toggle member switches from one side of the housing to the other at a controlled frequency.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described with reference to the accompanying drawings in which:

FIG. 1 is an exploded perspective view of a pneumatic latching relay according to the invention;

FIG. 2 is a side view in section of the pneumatic latching relay illustrated in FIG. 1;

FIG. 3 is a view similar to FIG. 2 showing one latching position of the relay;

FIG. 4 is a view like FIGS. 2 and 3 illustrating a second latching position of the relay;

FIG. 5 is a side view in section of a modified form of the pneumatic latching relay;

FIG. 6 is a side elevational view in section of a third and fourth embodiment of the invention;

FIG. 7 is an enlarged perspective view of a control element of the relay illustrated in FIG. 6;

FIG. 8 is a slightly enlarged partial sectional view taken along lines 88 of FIG. 6;

FIGS. 9-12 are partial schematic views of one input channel of the relay illustrated in FIG. 6, showing different forms of use of the relay; and

FIG. 13 is a side elevational view in section like FIG. 6 and illustrates a fifth embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings and to FIG. I in particular, there is illustrated a pneumatic latching relay comprising a box made of insulative material having reinforced side walls 14 and 16 which include vertical slots 18 and 20 respectively. End walls 22 and 24 and a flexible bottom wall 26 complete the box structure. A top 28 is provided for the box 12 in sealing relationship thereto, the top having a port 30 connected to a vacuum supply hose 32 and a port 34 connected to a vacuum supply hose 36. A spring contact member 38 is secured to the bottom of one side of the cover 28 in operative relationship with a fixed contact button 40. Electrical leads 42 and 44 are connected respectively to the spring contact member 38 and the fixed contact button 40. In like manner, aspring contact member 46 and a fixed contact button 48 are secured to the other side of the top 28 and are connected'to electrical leads 50 and 52 respectively.

A cylindrical cavity 54 is formed in the underside of the top 28. Ports 56 and 58 extend through the top into the cavity 54 and provide communication between the cylindrical cavity 54 and a pair of pneumatic control hoses 60 and 61 respectively. These hoses 60 and 61 can be connected together by a Y connection (not shown) for operation from a single source or can be coupled to separate control sources (not shown).

A diaphragm divides the box 12 into two sections and comprisesa rigid diaphragm frame 62 having any upper slot 64. The frame 62 lies within the slots 18 and of the box sidewalls l4 and 16 respectively and within a slot in the bottom wall 26. The sides of the frame 62 are relatively rigid whereas the bottom of the frame is made of thinner material so that it can flex slightly upwardly. I

The diaphragm has a central portion thereof which is divided into lower and upper movable members 70 and 74. Hinge 72 separates the bottom of the frame 62 from the lower movable member 70 and hinge 76 separates the lower movable member 70 from the upper movable member 74. In like manner, hinges 78 and 80 separate the upper movable member from portions of the diaphragm frame 62.

The sides of the lower and upper movable members 70 and 74 are freely movable with respect to the sides of the diaphragm frames 62. Flexible diaphragm members 82 and 84 are secured in the open space between the movable members 70 and 74 and the sides of the frame 62. Thus, the diaphragm forms an integral unit which is air impermeable. The flexible diaphragm members 82 and 84 are formed of some stretchable and flexible material such as rubber. The remainder of the diaphragm, i.e., the frame 62 and the movable members 70-and 74, are made from any suitable air impermeable material, such as a plastic. Polyethylene or polypropylene or polyvinylchloride are suitable for this part because these materials form a living hinge as required for the movable members 70 and 74.

A switch actuator 86 serves as a control member, having a cylindrical central portion 88 with a lower slot 90 designed to fit over and engage the top edge of the movable upper portion 74 of the diaphragm. Valving grooves 92 and 94 are provided at the top of the cylindrical portion 88 with the groove 92 extending from the top thereof to the left side (as viewed in FIG. 1) and the valving groove 94 extending from the top to the right side of the central portion 88.

Arms 96 and 98 extend laterally from either side of the central portion 88 to form actuators for the spring contact member 38 and 46.

In assembling the relay, the switch actuator 86 is positioned in the slot 64 of the diaphragm frame 62 with the slot 90 of the cylindrical central portion 88 engaging the upper movable member 74. Thus, the switch actuator 86 moves with the movement of the upper movable member 74. The diaphragm is positioned in the box 12 with the frame 62 positioned in the slots 18 and 20 of sidewalls 14 and 16. The top 28 is then placed on the box 12 in sealing relationship thereto. In this position. the upper surface of the cylindrical portion 88 of the switch actuator 66 is journaled within the cylindrical cavity 54.

The box is so constructed so that when theparts are assembled as described above and as viewed in FIG. 2, the diaphragm seals one side of the box from the other. Suitable sealing members (not shown) can be provided to assure the integrity of the seals.

Reference is now made to FIG. 2 which shows the relay in a normal inoperative condition. In this position, the bottom wall 26 of the box is perfectly flat and the diaphragm is planar in configuration. The arms 96 and 98 of switch actuator 86 are substantially horizontal and the spring contact members 38 and 46 are separated from the respective contact buttons and 48.

The operation of the pneumatic relay will now be described with reference to FIGS. 3-and 4. Initially, vacuum is drawn on both sides of the box through vacuum hoses 32 and 36. The bottom wall being the most flexible will tend to buckle upwardly with the vacuum pressure, thus buckling the diaphragm at the central portion thereof so that the movable members 70 and 74 buckle to one side of the box 12 with respect to the diaphragm frame 62. Assuming that the movable members 70 and 74 initially buckle to the left as illustrated in FIG. 3, the switch actuator 86 will be rotated slightly in a clockwise direction to force the arm 98 against the spring contact 46. This pressure from arm 98 will cause .the spring contact member to close against the fixed contact button 48. In this condition, leads and 52 will thus be in communication and leads 42 and 40 will be in an open circuit.

Pulses'of air can be supplied to the pneumatic control hoses 60 and 61 (which can be connected through a common connection). With the actuator 86 in the position illustrated in FIG. 3, the groove ;92 will be in communication with the port 56 whereas the groove 94 will be out of communication with the port 58. Thus, a

pulse of air to the pneumatic control hoses 60 and 61 will cause the pulse to be supplied to the left side of the box when viewed in FIG. 3. If the pulse is relatively weak, it will cause a slight counterclockwise movement of the switch actuator 86 to separate the spring contact 46 from the fixed contactbutton 48. Thus, the circuit including leads 50 and 52 will be temporarily interrupted.

However, when the pulse of air reaches a predetermined pressure or duration, the air pressure in the left side of the box will be sufficient to push the movable members and 74 to the right side of the box as illustrated in FIG. 4. At this time, the pressure of the bottom wall 26 causes the movable members 70 and 74 to snap to the buckled position on the right. Thus, the switch actuator 86 rotates in a counterclockwise direction, forcing the spring contact member 38 into operative contact with the fixed contact button 40. As a result, the circuit including the leads 42 and 44 is closed and the circuit including the leads 50 and 52 is open. Thus, the latching device is operated by pulses of air to change from one condition, i.e., circuits 50 and 52 closed, to another condition, i.e., circuit with leads 42 and 44 closed.

The novel diaphragm provides the requisite snap action in a relatively simple and inexpensive element. The entire relay can be made with relatively small parts and will be extremely light in weight compared with other relays of similar size;

Reference is now made to FIG. 5 for a description of a modified form of the invention.

In FIG. 5, a box 100 includes sidewalls 102 and 104, top wall 106 and a flexible bottom wall 108. Other sidewalls (not shown) can also be provided.

Pneumatic control hoses 110 and 112 supply pulses of air alternately to either side of the box. Desirably, a valve (not shown) directs the pulses of air into either hose 110 or hose 112.

A spring contact member 114 and a fixed contact button 116 are secured in operative relationship to the sidewall 102. In like manner, a spring contact member 118 and a fixed contact button 120 are secured to the other sidewall 104.

The diaphragm plate l22-has an outer frame 124 and movable upper and lower portions 126 and 128 respectively. The upper and lower portions are separated from each other and from the outer frame through hinges in the same fashion as the upper and lower members 74 and 70 respectively illustrated in FIGS. 1-4.

The sides of the outer frame are separated from the movable upper and lower portions 126 and 128 by flexible diaphragm members 134 in the same fashion as flexible diaphragm members 82 and 84 in the diaphragm illustrated in FIGS. 1-4. Acutator members 130 are provided on either side of the movable upper portion 126 for operable contact with the spring contact members 114 and 118. A spring 132 forces the flexible bottom wall upwardly to buckle the movable portions 126 and 128 with respect to the frame 124.

The modified form of the invention illustrated in FIG. 5 works substantially the same as the embodiment illustrated in FIGS. l-4. Initially, the spring 132 applies pressure to buckle the movable portions 126 and 128 with respect to the frame 124. Assuming that the buckling causes the movable members 126 and 128 to move to the left, the spring contact 118 is closed against the fixed contact button 120, thereby closing a first circuit. As illustrated in FIG. 5, leads are secured to the spring contact member 118 and the fixed contact button 120.

A pulse of air directed through the control holes 112 will cause a movement of the movable members 126 and 128 to the right as viewed in FIG. 5. If the pulse is relatively weak, it will merely momentarily separate the spring contact 118 from the fixed contact button 120. If the pulse is strong enough, it will cause the movable members 126 and 128 to toggle to the other side of the box, thereby closing spring contacts 114 against the fixed contact button 116. Thus, a second circuit is closed when the movable members 126 and 128 toggle to the right. In lieu of the two piece electrical switch shown in FIG. 5, a common ground can be attached directly to the actuator member 130. A circuit will be complete when the actuator member 130 touches a contact at either side of the box.

The pneumatic latching relay can be used in many different types of logic circuits where pneumatic signals are received and electrical signals are employed. Thus, the relay senses the pneumatic signals and converts them to electrical signals. The relay can be used to control higher energy electrical signals with pheumatic signals.

The relay finds uses in binary systems which employ pneumatic signals to control storage or electrical processes. The relay can be used as an AND gate, an OR gate. or a NOR gate in these types of systems.

Referring now to FIGS. 6-8, there is shown a third embodiment of the invention wherein a pneumatic flipfiop relay is used as a relay in a pneumatic system. The

box 12 is formed in the same fashion as the box of FIGS. 1-4 and includes sidewalls 22 and 24 and bottom wall 26. A cover 28a.is sealinglyfltted to the top of the box. The flip-flop diaphragm is substantially the same in this embodiment as shown in FIGS. l-4 including the rigid diaphragm frame 62, the lower movable member and the upper movable member 74. A cylindrical control member 136 has a slot 138 through which the control member 136 is mounted to the upper movable member 74. Elongate grooves 140, 142, 144, 146, 148 and 150 are formed in the cylindrical control member 136. As illustrated in FIG. 7, the elongate grooves 140-150 are positioned outside of a central area defined by the dotted imaginary lines 152 in FIG. 7.

The underside of the cover contains a cylindrical cavity 154 which is closely dimensioned to the size and shape of the cylindrical control member 136. Pairs of ports 156, 158, and 162 are provided through the top 28a and into the cylindrical cavity 154. One port of each pair of ports 156 and 158 falls within the central area defined by the imaginary lines 153 within the cylindrical cavity 154. Both pairs of ports 160 and 162 fall within the imaginary lines 153.

When the top 28a is on the box, the cylindrical control element 136 fits snugly within the cylindrical cavity 154. When the diaphragm is in the neutral position, i.e., when the lower and upper movable members 70 and 74 are straight up, the lines 152 on the control member 138 and 153 on the cavity 154 coincide so that the ports 160 and 162 will be in facial contact with the cylindrical area within the dotted lines 152. Thus, when the diaphragm is in the neutral or central position, none of the control lines 164 will be in communication with each other or with any part of the box 12. When vacuum is applied to the box through lines 32 and 36, the diaphragm will toggle to one side or the other as illustrated in FIG. 6. When the diaphragm has buckled to the left as viewed in FIG. 6, the left port of ports 162 and 160 will respectively be in communication with the elongated grooves 142 and 146. Thus, pressure applied through ports 160 and 162 will be applied to the left side of the box 12 as viewed in FIG. 6, causing a pulsing of the diaphragm or causing the diaphragm to toggle to the right side of the box. Further, when the valve is in the position illustrated in FIG. 6, the ports 158 will be in communication through the elongate groove 150. Thus, a pneumatic circuit is made between control lines leading to the ports 158 through groove 150.

When the diaphragm is toggled to the right side as viewed in FIG. 6 (not shown), the right (as viewed in FIG. 8) one of the ports 160 and 162 will be in communication respectively with grooves 144 and 140. Further, the ports 156 will be in communication through the elongate groove 148. In similar fashion, air pressure applied to either of the ports 160 or 162 will be transmitted to the rightside of the box to pulse the diaphragm or cause it to toggle to the left side. Ports 160 and 162 can be connected to a common source or can be connected to separate control lines.

the same or a different type of control system. In FIG. 9, the input control lines 164a and 1641') are connected together in a Y. Thus, a control pulse to the Y will result in a switching of the diaphragm to the opposite side of the box, regardless of which side the diaphragm is In FIG. 10, each input line 164a and 164b is connected to a separate source. Thus, an input pulse to line 164a will only result in switching the diaphragm from the left side to the right side. If the diaphragm is already on the right side, a pulse to control line 164a in the embodiment shown in FIG. will have no effect. In a similar manner, control pulses to line 164b will only switch the diaphragm from the right side to the left side. Thus, the valve arrangement in FIG. 10 is a setreset flip-flop relay.

In FIG. 11, the control line 162b is connected to a high pressure source 166 through a bleed valve 168 which permits the air pressure to flow slowly through line 1621:. Thus, a control pulse to line 162a will cause the diaphragm to toggle from the left side to the right side. However, the toggle will be reset after a predetermined length of time due to the slow flow of air pressure from the high pressure source 162 through control line 164b. Thus, the configuration of FIG. 11 results in the pneumatic flip-flop relay operation as-a monostable multivibrator.

In the embodiment illustrated in FIG. 12, the pneu matic flip-flop relay operates as a bistable multivibrator. Input lines 164a and 164b are connected through a Y to a high pressure source 166 through a bleed valve 168. The diaphragm will have air fed at a slow rate to the side of the valve on which the diaphragm is toggled. In other words,if the diaphragm is toggled to the left side, the air will be fed at a slow rate to the left side of the valve until such time as the valve toggles to the right side. The flow of air will then proceed to the right side of the diaphragm until the diaphragm toggles back to the other side.

In the embodiments illustrated in FIGS. 11 and 12,

the flow of high pressure gas through the bleedervalve 168 must be controlled with respect to the rate of vacuum withdrawal through lines 36 and 32 so that there is a net positive pressure build-up as a result of the supply of fluid pressure in the respective sides of the relay. In other words, in the embodiment illustrated in FIG. 11, the flow of fluid pressure through lines 164b must be greater than the rate of vacuum withdrawal through line 32 (FIG. 6). Similarly, the flow of gas through lines 164a and l64b and through the bleeder valve 168 in the embodiment illustrated in FIG. 12 must be greater than the rate of vacuum withdrawal through lines 32 and 36 (FIG. 6). Referring again to FIG. 6, a mechanical actuator 170 extends through an opening 166 in wall 24. The inner end of the actuator 170 is connected to the lower movable member 70 of the diaphragm at a connection 172. The actuator 170 is sealed by accordion sleeve 168 to maintain the sealed condition of the box. As the diaphragm switches from one side of the box 12 to the other, the mechanical actuator reciprocates within the opening 166. The movement of the actuator 170 can be used to control any type of mechanical switching device, or to control the mechanical motion of various devices such as wheels, levers, etc.

Another form of a mechanical actuator is illustrated in- FIG. 13 to which reference is now made. In FIG. 13,

like numerals have been used to designate like parts.

The embodiment of FIG. 13 is substantially the same as the embodiment of FIGS. 6-8 except that a mechanical actuator 174 is secured to the cylindrical control element 136 and extends through slot 176 in the cover 280. As the diaphragm toggles back and forth and the cylindrical control element 106 rotates in cavity 154,

the mechanical actuator 174 moves back and forth in slot 176 to operate any suitable mechanical device.

Reasonable variation and modification are possible within the scope of the foregoing disclosure, the drawings, and the appended claims without departing from the spirit of the invention. I

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. A bistable snap-action toggle relay comprising:

a sealed housing separated into compartments has been inserted by a diaphragm;

switch means coupled to the diaphragm and operated by buckling movement of said diaphragm;

means for applying a differential fluid pressure to opposite sides of said diaphragm to cause movement of said diaphragm between a position on one side of said housing and a position on the other side of said housing and vice versa;

v said diaphragm comprising a relatively thin, stiff toggle member normally of flat planar configuration and means for resiliently buckling said toggle member laterally of the plane thereof when a force parallel to said plane is applied substantially perpendicular to an edge of said diaphragm; and

means for applying a force substantially perpendicular to said edge of said diaphragm and parallel to a the plane thereof to buckle said toggle member to one side of said housing.

2. A pneumatic snap-action toggle relay according to claim 1 wherein said force applying means applies force resiliently to permit said toggle member to snap to either side of said housing upon application of differential pressure across said diaphragm.

3. A pneumatic snap-action toggle relay according to claim 2 wherein said toggle member comprises planar portions of a sheet of stiff material, which portions are hinged together along a common edge.

4. A pneumatic snap-action toggle relay according to claim 3 wherein said diaphragm further includes a stretchable membrane joined to said toggle member to permit stretching said diaphragm member during deformation of said toggle member.

5. A pneumatic snap-action toggle relay according to claim 4 wherein said housing has a flexible wall, said edge of said toggle member abuts said flexible wall, and said force applying means-includes the application of a differential gas pressure to the bottom of said housing.

6. A pneumatic snap-action toggle relay according to claim 4 wherein said housing has a flexible wall, said edge of said toggle member abuts said flexible wall, and said force applying means includes means to apply an inward force to said flexible wall.

7. A pneumatic snap-action toggle relay according to claim 3 wherein said housing has a flexible wall, said edge of said toggle member abuts said flexible wall, and

said force applying means includes means to apply a force to said flexible wall.

8. A pneumatic snap-action toggle relay according to;

I claim 1 wherein said switch means includes a control member; means journaling said control member for rotational movement between a first rotational position wherein said toggle member is buckled to one side of said housing and asecond rotational position wherein said toggle member is buckled to the other side of'said housing.

9. A pneumatic snap-action toggle relay according to claim 8 wherein said switch means further includes an electrical switch contact mounted on said housing, and means coupled to said control member for operating said electrical switch contact as said control member moves from said first position to said second position.

10. A pneumatic snap-action toggle relay according to claim 8 wherein said switch means includes a groove in said control member in fixed contact with said journaling means, and a pair of ports extending through said journaling means, said ports being in registry with said groove in said control member when said control member is in said first rotational position and out of registry with said groove when said control member is in said second rotational position.

11. A pneumatic snap-action toggle relay according to claim 8 wherein said differential pressure applying means includes grooves in said control member, said grooves communicating with said one side of said housing when said control member is in said first position and in communication with said other side of said housing when said control member is in said second position and conduit means extending through said journaling means and communicating with said grooves for selectively switching said toggle member from said one side of said housing to said other side and vice versa.

12. A pneumatic snap-action toggle relay according to claim 11 wherein said conduit means are connected.

13. A pneumatic snap-action toggle relay according to claim 12 and further comprising means for supplying pressure to said conduit means at a controlled rate so that said control member alternates between said first and second positions at a controlled rate.

14. A pneumatic snap-action toggle relay according to claim 11 wherein said conduit means comprise two separate conduits, one coupled to said one side of said housing when said control member is in said first position and the other coupled to the other side of said housing when said control member is in said second position.

15. A pneumatic snap-action toggle relay according to claim 14 and further comprising means to supply pressure to said one conduit at a controlled rate so that said control means is automatically reset to said second position after being switched to said first position.

16. A pneumatic snap-action toggle relay according to claim 1 wherein said switch means includes an actuator member secured to said diaphragm and linearly movable therewith for operating elements by mechanical means.

17. In a pneumatic relay comprising a pneumatic operated diaphragm and switch means coupled to said diaphragm and operated thereby, the improvement comprising:

said diaphragm being a relatively planar toggle member and having means for resiliently buckling a portion of said diaphragm laterally of the plane of said diaphragm by the application of a force substantially perpendicular to an edge thereof and parallel to the plane of said diaphragm;

a control member mounted on said diaphragm edge for movement therewith and which actuates said switch means; and

means journaling said control element for rotational movement on said diaphragm edge between a first position and a second position whereby buckling of said diaphragm causes rotational movement of said control element.

18. A pneumatic relay according to claim 17 wherein said switch means further includes an electrical switch contact mounted on said housing and means coupled to said control member for operating said electrical switch contact as said control member moves from said first position to said second position.

19. A pneumatic relay according to claim 17 wherein said switch means includes a groove in said control member in facial contact with said journaling means, and a pair of ports extending through said journaling means, said ports being in registry with said control member when said control member is in said first rotational position and out of registry with said groove when said control member is in said second rotational position.

20. A pneumatic relay according to claim 17 and further comprising grooves in said control member, said grooves communicating with one side of said diaphragm when said control member is in said first position and communicating with the other side of said diaphragm when said control member is in said second po sition, and conduit means extending through said journaling means and communicating with said grooves for selectively switching said diaphragm to rotate said control member between said first and second positions.

21. A pneumatic relay according to claim 20 wherein said conduit means are connected.

22. A pneumatic relay according to claim 21 and further comprising means for supplying pressure to said conduit means at a controlled rate so that said control member alternates between said first and second positions at a controlled rate.

23. A pneumatic relay according to claim ZOwherein said conduit means comprise two separate conduits, one coupled to one side of said diaphragm when said control member is in said first position and the other coupled to the other side of said diaphragm when said control member is in the second position.

24. A pneumatic relay according to claim 23 and further comprising means to supply pressure to said one conduit at a controlled rate so that said control member is automatically reset to said second position after being switched to said first position.

25. A pneumatic relay according to claim 17 wherein said switch means includes an actuator coupled to said diaphragm for movement therewith to operate elements by movement of said actuator. 

1. A bistable snap-action toggle relay comprising: a sealed housing separated into compartments has been inserted by a diaphragm; switch means coupled to the diaphragm and operated by buckling movement of said diaphragm; means for applying a differential fluid pressure to opposite sides of said diaphragm to cause movement of said diaphragm between a position on one side of said housing and a position on the other side of said housing and vice versa; said diaphragm comprising a relatively thin, stiff toggle member normally of flat planar configuration and means for resiliently buckling said toggle member laterally of the plane thereof when a force parallel to said plane is applied substantially perpendicular to an edge of said diaphragm; and means for applying a force substantially perpendicular to said edge of said diaphragm and parallel to the plane thereof to buckle said toggle member to one side of said housing.
 2. A pneumatic snap-action toggle relay according to claim 1 wherein said force applying means applies force resiliently to permit said toggle member to snap to either side of said housing upon application of diffeRential pressure across said diaphragm.
 3. A pneumatic snap-action toggle relay according to claim 2 wherein said toggle member comprises planar portions of a sheet of stiff material, which portions are hinged together along a common edge.
 4. A pneumatic snap-action toggle relay according to claim 3 wherein said diaphragm further includes a stretchable membrane joined to said toggle member to permit stretching said diaphragm member during deformation of said toggle member.
 5. A pneumatic snap-action toggle relay according to claim 4 wherein said housing has a flexible wall, said edge of said toggle member abuts said flexible wall, and said force applying means includes the application of a differential gas pressure to the bottom of said housing.
 6. A pneumatic snap-action toggle relay according to claim 4 wherein said housing has a flexible wall, said edge of said toggle member abuts said flexible wall, and said force applying means includes means to apply an inward force to said flexible wall.
 7. A pneumatic snap-action toggle relay according to claim 3 wherein said housing has a flexible wall, said edge of said toggle member abuts said flexible wall, and said force applying means includes means to apply a force to said flexible wall.
 8. A pneumatic snap-action toggle relay according to claim 1 wherein said switch means includes a control member mounted on a rotatable edge of said toggle member; means journaling said control member for rotational movement between a first rotational position wherein said toggle member is buckled to one side of said housing and a second rotational position wherein said toggle member is buckled to the other side of said housing.
 9. A pneumatic snap-action toggle relay according to claim 8 wherein said switch means further includes an electrical switch contact mounted on said housing, and means coupled to said control member for operating said electrical switch contact as said control member moves from said first position to said second position.
 10. A pneumatic snap-action toggle relay according to claim 8 wherein said switch means includes a groove in said control member in fixed contact with said journaling means, and a pair of ports extending through said journaling means, said ports being in registry with said groove in said control member when said control member is in said first rotational position and out of registry with said groove when said control member is in said second rotational position.
 11. A pneumatic snap-action toggle relay according to claim 8 wherein said differential pressure applying means includes grooves in said control member, said grooves communicating with said one side of said housing when said control member is in said first position and in communication with said other side of said housing when said control member is in said second position and conduit means extending through said journaling means and communicating with said grooves for selectively switching said toggle member from said one side of said housing to said other side and vice versa.
 12. A pneumatic snap-action toggle relay according to claim 11 wherein said conduit means are connected.
 13. A pneumatic snap-action toggle relay according to claim 12 and further comprising means for supplying pressure to said conduit means at a controlled rate so that said control member alternates between said first and second positions at a controlled rate.
 14. A pneumatic snap-action toggle relay according to claim 11 wherein said conduit means comprise two separate conduits, one coupled to said one side of said housing when said control member is in said first position and the other coupled to the other side of said housing when said control member is in said second position.
 15. A pneumatic snap-action toggle relay according to claim 14 and further comprising means to supply pressure to said one conduit at a controlled rate so that said control means is automatically reset to said second position after being switched to said First position.
 16. A pneumatic snap-action toggle relay according to claim 1 wherein said switch means includes an actuator member secured to said diaphragm and linearly movable therewith for operating elements by mechanical means.
 17. In a pneumatic relay comprising a pneumatic operated diaphragm and switch means coupled to said diaphragm and operated thereby, the improvement comprising: said diaphragm being a relatively planar toggle member and having means for resiliently buckling a portion of said diaphragm laterally of the plane of said diaphragm by the application of a force substantially perpendicular to an edge thereof and parallel to the plane of said diaphragm; a control member mounted on said diaphragm edge for movement therewith and which actuates said switch means; and means journaling said control element for rotational movement on said diaphragm edge between a first position and a second position whereby buckling of said diaphragm causes rotational movement of said control element.
 18. A pneumatic relay according to claim 17 wherein said switch means further includes an electrical switch contact mounted on said housing and means coupled to said control member for operating said electrical switch contact as said control member moves from said first position to said second position.
 19. A pneumatic relay according to claim 17 wherein said switch means includes a groove in said control member in facial contact with said journaling means, and a pair of ports extending through said journaling means, said ports being in registry with said control member when said control member is in said first rotational position and out of registry with said groove when said control member is in said second rotational position.
 20. A pneumatic relay according to claim 17 and further comprising grooves in said control member, said grooves communicating with one side of said diaphragm when said control member is in said first position and communicating with the other side of said diaphragm when said control member is in said second position, and conduit means extending through said journaling means and communicating with said grooves for selectively switching said diaphragm to rotate said control member between said first and second positions.
 21. A pneumatic relay according to claim 20 wherein said conduit means are connected.
 22. A pneumatic relay according to claim 21 and further comprising means for supplying pressure to said conduit means at a controlled rate so that said control member alternates between said first and second positions at a controlled rate.
 23. A pneumatic relay according to claim 20 wherein said conduit means comprise two separate conduits, one coupled to one side of said diaphragm when said control member is in said first position and the other coupled to the other side of said diaphragm when said control member is in the second position.
 24. A pneumatic relay according to claim 23 and further comprising means to supply pressure to said one conduit at a controlled rate so that said control member is automatically reset to said second position after being switched to said first position.
 25. A pneumatic relay according to claim 17 wherein said switch means includes an actuator coupled to said diaphragm for movement therewith to operate elements by movement of said actuator. 